MICROSTRUCTURE AND PROPERTIES OF Al2O3 sf／Al－1．5Mg COMPOSTITE MANUFACTURED BY EXTRUSION DIRECTLY FOLLOWING LIQUID INFILTRATION
(School of Materials Science and Engineering; Harbin Institute of Technology; Harbin 150001)
Abstract: The microstructure and properties of short alumina fiber reinforced Al-1.5Mg composite(Al2O3sf/Al-1.5Mg) manufactured by extrusion directly following liquid infiltration (EDFLI) were experimentally investigated.It was found that the microstructure of Al2O3sf/Al-1.5Mg composite is characterized by a well-densified matrix,with fine recrystallized grains and free from microvoids and non-wetting defects,and quite uniformly and quasi unidirectionally distributed fibers maintaining adequate aspect ratios,which leads to a better strengthening effect.It was also found that the mechanical properties E,σ0.2,σb and the thermal expansion resistance of the composite simultaneously increase with the enhancement of the fiber volume fraction while the elongation δ is still maintained at a relative high level.Besides,the Al2O3sf/Al-1.5Mg composite possesses corrosion resistance equivalent to that of the Al-1.5Mg alloy.
Key words: Al2O3sf/Al-1.5Mg composite microstructure properties extrusion infiltration